I wanted to do a quick writeup for an incredibly easy way to add a professional looking electric fan setup on our trucks for less than $300 for a 3-core radiator or less than $250 for a 2-core.

Here are the parts used, as pictured in the attachement:

* (2) Flex-A-Lite 12" fans - I purchased from Classic Heartbeat, Wes has them readily in stock. This unit is not sold in stores - it's part of their "pro air electric fan" line and it is NOT listed at their website. This is a heavy duty version of the Flex-A-Lite part number "112", it flows more air, costs about 8 bucks more. I believe the 2-core radiator would only use 1 fan. This is Flex-A-Lite part number "212".

* (6) self-tapping 8-18 x ¾ screws

* (6) neoprene 3/8-OD washers (optional)

* (8) bolts - 1" length will work fine, I got 1¼" and they're a tad long

* (1) Fan shroud - this is a custom fabbed piece that is made exclusively by Wes at ClassicHearbeat.com, and it comes in a 2-12" fan setup or a 1-12" fan setup. I assume the 2-core radiator will use the 1-12" fan setup. I got mine powdercoated in "Silver vein" from GMCPauls for $129. This is an incredibly nice piece, superior quality!

You can add another $20-40 to that total depending on how you wire it. Wiring instructions are inside the box. Flex-A-Lite sells a temperature sensor setup for these fans on the cheap...might be worth looking into if you won't have a computer to control yours like I do.

I went with this list because it is literally a direct bolt-up, no real drilling required. You could opt to cheap out on it and hit the junkyard and find some fans, but .... you're going to end up needing to hack or drill the shroud and that just wasn't an option for me. I initially purchased some Mr. Gasket 12" fans and they DID NOT fit the hole provisions given in this shroud (they cost the same as the F-A-L fans from Classic Heartbeat).

The fan shroud Classic Heartbeat makes is a direct boltup for a stock radiator. Wes makes it to specifically fit the Flex-A-Lite fans he sells, so no drilling of the shroud is required, just bolt the fans to the shroud, clamp the shroud in place on the radiator, drill pilot holes into the top and bottom rail of the radiator, then use the self tappers with the washers to finish the job and you're done. You can buy this unit pre-fitted with fans and pre-wired from Wes for about $50-150 more, depending on which shroud you go with.

Finally, since someone is bound to ask...."How do you know if you have a 2-core or a 3-core radiator?" - Well, the 3-core is wider, and uses the widest mount configuration possible on the radiator core support. The 3-core fits about 1-2 inches away from the battery tray, whereas the 2-core will be 5-6 inches away from the battery tray.

Next, decide if you're going to mount your fans on the front of the radiator (between grill and radiator, pushing air), or on the back of the radiator (between engine and radiator, pulling air). These Flex-A-Lite fans support both setups. Most fans are mounted and wired out-of-the-box to pull air if you put (+) power to the red wire and (-) ground to the black wire. Be sure to read the instructions for the fan you choose to figure out whether you just need to flip the fan blade *or* reverse the polarity of the wiring to convert the fan from a puller into a pusher in case you require this for your setup.

Test fit the shroud over the radiator. I lined mine up on the top and bottom rail of the radiator, then used the 'quick clamps' I have for woodworking to clamp it at the top and bottom.

Then I drilled some pilot holes for the self-tapping screws (makes life easier), and did an initial seating of the shroud using the screws and washers. You can see in the pictures below how the shroud fits over the core itself and butts up against the rail on top and bottom of the radiator.

Once you've test-fitted your shroud, pull it off again to mount the fans.

The fans come with flush-mount tabs as shown in the pictures below - they slide right into the fan.

As recommended by Wes, I bought the rubber grommets above to cut down on vibration. ¼" grommets are a perfect fit and pop right in. Anything larger than 5/16" was too big.

Insert grommets in the 8 fan mount provisions (pictured below).

Insert the 4 flush-mount fan tabs into each fan you're using.

Be sure to think about where you will be routing your wires BEFORE you mount the fans. Will you go along the bottom of the core support, or will you try to tie into the existing wire run across the top of the core support? Think about this before you bolt up the fans

Place the fan on the shroud and line it up. From the bottom up, I mounted things up like this:

nut
washer
fan flush-mount clip
shroud/grommet
washer
bolt head

I chose to use washers so the bolt wouldn't pull through the grommet on the bottom or the clip on the top. I chose the stop nuts because they tend to not come loose with vibration, and I didn't feel like using lockwashers. I chose to fit the bolt with the head closest to the radiator to leave the least possible amount of bolt protruding into the radiator. Obviously, you can do this any way you want.

Now is the time to decide what to use for an electrical/wiring setup. Here are some tips on wiring so you don't screw your stuff up:

* Regardless of what you do, wire things SAFELY -- Use a 20A inline fuse (or breaker) for each fan
* Just like you would rewiring your headlights, use a relay to deliver the power if you're putting a switch inside the vehicle (you can also use relays with the temperature sensor setup sold by F-A-L, Mr. Gasket and other companies).
* When supplying power for the relay, be sure to use an IGN (hot when "on") lead. If you give direct battery power, the fans can cut on when the truck is off and drain your battery.

Once you're wired up and ready to go, fit your radiator hoses back on, fill up with coolant and turn on the vehicle to test your setup.

If you went with a black shroud rather than the silver vein like I did, it would be very hard to tell that this was not a stock setup - the pictures do not do this fan shroud justice - it is really, really nice!

The only thing I thought could have been added is an additional 2-hole provision to mount your relays directly to the shroud, and maybe plastic caps so people can plug those holes if they aren't required.

For some bigger version of the install pictures, I'll leave these links here:

Big thanks to Wes at ClassicHeartbeat and Les at GMCPaul's for helping me find and get these parts. Both of them were very eager to help and their prices beat anything else I found on the web hands-down. These two companies are a pleasure to deal with and I would recommend them over LMC or any other big-name vendor out there in a heartbeat. It also felt great to support a board vendor.

Personalized, friendly service and a true interest in supporting customers on the phone or via email is a huge plus with them. I ntalking to them, it is quite clear they truly share the same passion for these trucks that many of the rest of us do.

If you have any questions about the shroud, call Wes (number is at the Classic Heartbeat website) and ask - I did! He was happy to answer everything.

It's supposed to a direct bolt in kit and comes with temp sensors. CPP did a write up install: http://www.classicperform.com/tech_a.../Fantastic.htm
Are you going to have your truck ready to drive to the Turkey Run? Keep plugging away man, you're almost there! Thanks again.

I believe the lower hose outlet is 1¾" and the upper is 1½" on this radiator, per the Napa site. Crappy part is the LS1 water pump bibs are ~¼" smaller than their respective hookup to the radiator.

For the lower hose, I went with a 13.25" / 1¾" rubber flex hose from Advance Auto, part number '1313'. The trick is to use the longer rubber end (you'll see what I mean when you look at it) and install it on the lower radiator bib, then clamp it down, then install the radiator (if it's out) and clamp it to the water pump. It fits a tad loose, but nothing a hose clamp can't fix.

I looked quite heavily for a reasonably priced universal flex hose, but the prices are seriously a freaking joke. This is the cheapest I could find:

However, as you know, it's crucial to hookup the steam vent line on the GenIII motors, and I didn't want to hack a damned $80+ upper hose to insert a bung for this It's a tough choice. Because I went stock 3-core, it wasn't provisioned for this steam vent. You obviously can't use the radiator overflow bung. This radiator is tapped for ¼ NPT in the bottom (for the petcock), and supposedly you can use that, but I think it looks sloppy myself.

Alternately, You can drill and tap the water pump for the ¼" steam vent line and terminate there, or you can run it to the heater line, or you can drill and tap your radiator. I wasn't comfy with the latter of the three, so I'm (for now) running it out of the petcock provision, which will probably change before the first fire-up.

Damn, that is nice! I take it this bolts to the factory radiator clips (the top clips), right? Are the fans replaceable? What is the profile like (how far will it stick out? The kit I used is pretty low profile. Looks like that one uses 2 diff't fans also. It's really cool that it comes pre-wired with relays and everything though. What is all the wiring on the left hand side? Temp sensor? That's a pretty smokin' deal!

Quote:

Originally Posted by Hart_Rod

[Are you going to have your truck ready to drive to the Turkey Run? Keep plugging away man, you're almost there! Thanks again.

Rob

I doubt it. I was expecting to finish the last real big obstacle, which was the braided fuel lines, but by the time I got to working on those today, I had to come into work (where I am now) and I probably won't get them started, much less completed. I'll try when I get home, but bet the most I'll get done is mounting the FPR/filter to the framerail and maybe, just maybe, get the two shorter lines running to the tank.

I highly recommend checking out my thread at LS1tech (in my sig) for other information. I've had a fun time in the past couple of weeks getting stuff done. I have been posting a bit of it there. I really wanted to be done with the engine by turkey day, and I'm still trying to get my proposed clutch M/C bracket into CAD and sent off for milling.

Wow Shifty!! Great write up.... I would like to add that we have these on our website as complete assemblies. In aluminum, stainless steel, pollished stainless steel, painted steel, and offer a viriety of colors in powder coated. I would question 123classics claim to having the highest quallity unit though.. Our unit comes with all marine grade, heat shrink terminals, and stainless steel hardware. The shrouds are not plastic and secure better to the radiator. I do however like the idea of mounting the relays, and possibly the thermostat between the fans though... Anyway this write up isn't about the comparisons between systoms, it is about electric fans. I will say it again, GREAT WRITE UP SHIFTY!!! WES www.ClassicHeartbeat.com

You aren't going to find anything out there that uses the stock radiator clips that is more secure than Wes' package. This thing might as well be welded to the radiator - those 6 sheet metal screws put it ON the radiator and it ain't movin

Per the instructions I got with the fan, it can be a pusher OR a puller, and Wes was really smart with his fan shroud, it should be able to bolt to the front or the rear of the radiator, unlike the one that 123classics.com is selling.

I believe the Flex-A-Lite fans just need to have the fan blade reversed (single nut holds it on) to make it a pusher, whereas the Mr Gasket ones I bought before this (didn't fit!) required you to swap the wires.

This shroud is manufactured to fit the factory/stock radiator. While I'm sure it would work well, it wouldn't have the really kickass fitment on an aluminum radiator like it has on a stock radiator.

Let me jump on a soapbox for a second about aluminum radiators, because I think they are misunderstood and highly overrated: If you are not doing a buildup over 400-500 horsepower, and aluminum radiator is totally unnecessary, and in the case of a 4-row aluminum radiator, complete overkill IMO. Aluminum radiators only give ~10-15% more cooling per core. A 3-core brass/copper radiator cools nearly as well as a 2-core aluminum, a 4-core brass/copper cools nearly as well as a 3-core aluminum.

There is a forum member from DFW, Texas, that was running an LS1 in his truck @ 435HP with a stock 3-core copper/brass in the Texas heat, beating the hell out of it, and never overheated. The factory radiators in these trucks are great!

As for the question about where to find these for newer model trucks ... I am not sure. I would contact Wes @ ClassicHeartbeat.com and ask him, and also contact Les or Paul at GMCPauls.com